The present invention generally relates to laryngoscopes or larynegeal speculums, specifically to laryngeal blades of the type utilized for displacing the epiglottis to expose the entrance to the trachea, such as in intubation.
In the prior art, special instruments called laryngoscopes or laryngeal speculums such as shown in U.S. Pat. No. 2,289,226 to Foregger, are utilized to expose the larynx and epiglottis of asphyxiated or anaesthetized persons. Such instruments have a handgrip from which extends a laryngeal blade carrying a light source. Several types of blades are available, including generally straight blades which are inserted down the side of the oral cavity to the epiglottis, whereby the epiglottis may be displaced in order to permit placement of a tube into the trachea. Another type of blade, which is generally curved and usually is called the MacIntosh blade, having means to divert and hold the tongue to the side to expose the larynx, is inserted in the central part of the oral cavity between the base of the tongue and the epiglottis. By firmly drawing the instrument outward, the tissue superior to the epiglottis and the epiglottis itself may be so displaced as to gain access to the trachea. Inexperienced medical personnel utilizing this type of laryngoscope instead may pivot the blade against the upper front teeth in an unsuccessful attempt to displace the epiglottis, which in extreme cases may result in breaking of those teeth.